[Bug c/82752] New: Support %OB, %Ob strftime formats

[jsm28 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82752

            Bug ID: 82752
           Summary: Support %OB, %Ob strftime formats
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jsm28 at gcc dot gnu.org
  Target Milestone: ---

There is a POSIX proposal http://austingroupbugs.net/view.php?id=258 accepted
for issue 8 (the next major revision of POSIX, not yet in progress) for adding
a strftime %OB format (for nominative as opposed to genitive month names, in
languages where standalone months needs a different case from months used with
a day number).  This has apparently been in FreeBSD since 1999, and should soon
be going in glibc, along with corresponding %Ob (since it turns out abbreviated
months also need different cases in some languages).

GCC should support %OB and %Ob strftime formats in -Wformat (with due warning
for being extensions over ISO C with -Wformat -Wpedantic).  This will be needed
to avoid warnings for glibc tests of the new feature.